For those needle protection devices that have a housing either hingedly or flexibly connected to a base to which a needle is matable or extends, when the needle sheath is pivoted to cover the needle, as the needle retaining mechanism for example a hook inside the needle sheath makes contact with the needle and then flexes over to grip the needle, the relative movement between the needle and the housing is interrupted abruptly so as to cause vibrations to the needle due to the sudden deceleration and then acceleration of the needle relative to the housing. This sudden deceleration/acceleration of the needle relative to the housing causes the needle to vibrate or jerk such that whatever fluid the needle has carried thereon is splattered to the environment or atomized to the atmosphere. Given that the fluid carried by the needle usually consists of blood which may well carry some contagious diseases such as the HIV virus, any excessive splattering, splashing or aerosolizing of the contaminated blood into the environment needs to be avoided. Accordingly, there is a need for a needle protection device, and more particularly the sheath or housing to the needle protection device, that has a feature that substantially prevents a needle from vibrating or jerking when it is being enclosed by the sheath.
In Hollister U.S. Pat. No. 5,993,426, there is disclosed a needle sheath that has fitted to the distal end thereof a material such as for example cotton that can absorb fluid collected at the tip of the needle cannula. The material that is fitted to the distal end of the needle sheath acts to absorb fluid that may be collected at the tip of the needle, before the needle makes contact with the needle retaining hook, so as to prevent the splattering of the fluid when the needle does make contact with the hook. One problem with the '426 device is that it is difficult to manufacture since the liquid absorbent material most likely needs to be hand fitted and glued to the distal end of the needle. The manufacturing cost for the device disclosed in the '426 patent may also be unacceptably high due to the additional expense of the absorbent material.